Landing: 568d439f1d1f

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Project / Subsystem

gcc / i386

Date

2026-05-20

Author

Jakub Jelinek

Commit

568d439f1d1f65eabed55a54da812a865dc5c946

Source

github

Perf win

Breaking

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All attributes

project: gcc
subsystem: i386
patch_id: —
commit_hash: 568d439f1d1f65eabed55a54da812a865dc5c946
source_type: github
headline: i386: Fix Peephole2s With const359_operand
tldr: Fixes an ICE on i386 by ensuring peephole optimizations for multiplications avoid using the stack pointer as an index register.
author: Jakub Jelinek
outcome: committed
performance_win: false
breaking_change: false
series_id: —
series_parts: []
tags: • i386
• optimization
• bugfix
discussion_id_link: —
bugzilla_pr: —
url: https://github.com/gcc-mirror/gcc/commit/568d439f1d1f65eabed55a54da812a865dc5c946
date: 2026-05-20T00:00:00.000Z

This commit fixes an internal compiler error (ICE) on i386. The const359_operand peephole optimization was incorrectly attempting to transform multiplications of the stack pointer (%rsp) by 3, 5, or 9 into a lea instruction, which is invalid because the stack pointer cannot be used as an index register. The fix ensures that the optimization uses index_reg_operand to prevent the stack pointer from being used as an index register.